DNAzyme-Catalyzed Cellular Oxidative Stress Amplification for Pro-protein Activation in Living Cells.

The conditional control of protein function in response to the physiological change of cells is of great interest for studying protein function in biological settings and developing protein therapeutics. We report herein that catalase (CAT) DNAzyme can potentiate the generation of reactive oxygen species (ROS) in living cells by knocking down catalase expression, which could further activate a reactive oxygen species (ROS)-responsive pro-protein, RNase A-NBC, in situ. Using an optimized lipid nanoparticle delivery system to simultaneously introduce CAT DNAzyme and RNase A-NBC into cells, we show that the pro-protein, RNase A-NBC, could be activated in a significantly enhanced manner to prohibit tumor cell growth in different types of cancer cells. We believe the methodology of regulating pro-protein activity using DNAzyme biocatalysis to differentiate intracellular environment could further be extended to other functional proteins, and even fundamental investigations in living systems to develop pro-protein therapeutics.